Take This Waltz, starring Michelle Williams and Seth Rogen, debuted last Friday, June 29. Michelle's character Margot is a happily married woman who falls in love with the artist who lives across the street. But scandal aside, Margot dresses supercute in retro dresses, preppy plaids, and denim cutoffs — in short, she portrays the perfect casual-cool Summer style. Check out Michelle's wardrobe in the movie, then shop similar pieces for yourself.